/ _______________ \ / _______________ \ / _______________\
| / ____ / ___\| | / ____ / ___\| | / ____ |
| / 29 3*\/ 93 | 1 I*\/ 3 || | / 29 3*\/ 93 | 1 I*\/ 3 || | / 29 3*\/ 93 |
| 3 / -- + -------- *|- - - -------|| | 3 / -- + -------- *|- - + -------|| | 3 / -- + -------- |
| 1 1 \/ 2 2 \ 2 2 /| | 1 1 \/ 2 2 \ 2 2 /| | 1 1 \/ 2 2 |
1*(a + 0)*|a + - + -------------------------------------- + ------------------------------------|*|a + - + -------------------------------------- + ------------------------------------|*|a + - + ---------------------- + --------------------|
| 3 _______________ 3 | | 3 _______________ 3 | | 3 _______________ 3 |
| / ___\ / ____ | | / ___\ / ____ | | / ____ |
| | 1 I*\/ 3 | / 29 3*\/ 93 | | | 1 I*\/ 3 | / 29 3*\/ 93 | | / 29 3*\/ 93 |
| 3*|- - - -------|*3 / -- + -------- | | 3*|- - + -------|*3 / -- + -------- | | 3*3 / -- + -------- |
\ \ 2 2 / \/ 2 2 / \ \ 2 2 / \/ 2 2 / \ \/ 2 2 /